ABC News' Michael Falcone reports:

Rick Santorum is trying to eclipse Newt Gingrich as the conservative alternative to Mitt Romney and he is shooting for the moon.

Santorum has been disparaging Gingrich's plan, which he unveiled ahead of the Florida primary, to build a colony on the moon by the end of his second term if elected. His campaign evidently believes the issue has relevance beyond the Sunshine State.

The former Pennsylvania senator has penned a new Op-Ed lambasting Gingrich's proposal as yet another "wasteful" government program that defies the law of "fiscal sanity."

"Republican presidential candidate Newt Gingrich chose to blatantly pander to a Florida crowd on the space coast (known for its support for NASA) when he told them that as President, he would use taxpayer dollars to expand the role of the federal government in manned space exploration, with the goal of building a colony on the moon by the end of his second term," Santorum wrote."After this announcement, many Americans were left scratching their heads especially since Newt is more prone to quoting George Washington rather than George Jetson."

The Op-Ed is the latest in a series of attacks Santorum is hurling in Gingrich's direction both on the campaign trail and on the airwaves over the proposed lunar base.

Santorum's campaign released a satellite radio ad late last week titled "Out Of This World," in which he calls the idea "fiscal insanity" and "another reason true conservatives are uniting behind Rick Santorum."

And while campaigning in Missouri last week, Santorum blasted off on the issue.

"We need someone who is more multidimensional than Governor Romney and not as multidimensional - in every idea in the word - as Newt Gingrich," Santorum said. "I promise you: no moon colonies, I promise."

In his Op-Ed Santorum suggests stronger partnerships between government and the private sector as the answer to keeping America competitive in the new space race.

"The pioneers of flight and space exploration are inspiring to millions and the advancements that result are beneficial to our quality of life and also critical to our national security - particularly as China ramps up aggressively in this area," Santorum wrote. "But I am less concerned about creating a government program to build a colony on the moon more concerned reducing government to build a strong economy here on earth."

When Gingrich was asked on Sunday, in an interview with NBC's David Gregory on "Meet The Press," whether his lunar plans hurt his "seriousness" as a candidate, the former House speaker's resolve did not wane.

"Every serious analyst understands that the Chinese are going all out to dominate space, the Russians today have the only man-rated vehicle available to the United States in space," Gingrich said. "This was not some slip, this was a deliberate effort to start a conversation at a, at a time when the Chinese, the Indians and the Russians are aggressively moving into space and we are bureaucratically mired down in red tape spending billions of dollars without making very much progress."

Santorum rebutted Gingrich with the political equivalent of a full moon.

"Quite frankly," he added in the Op-Ed, "it's hard to take the Speaker seriously as a fiscal conservative when he puts these extravagant expensive ideas over the economic well being of the next generation."